FABRICATION OF A POLYMER-ON-SILICA HYBRID THERMO-OPTIC SWITCH WITH FAST RESPONSE TIME AND LOW POWER CONSUMPTION

A polymer-on-silica Mach–Zehnder interferometer (MZI) TO switch is experimentally demonstrated using core polymer material with large thermo-optic (TO) coefficient. In the hybrid structure, the negative photoresist SU-8 and silica are used as core and lower cladding, respectively. Wet-etching technique is adopted to optimize fabrication process and diminish sidewall roughness and scattering loss. Compared to our two previously reported works, this switch exhibits better performance with lower power consumption of less than 4.8 mW, higher extinction ratio of 22.5 dB, shorter rise time of 141 μs and fall time of 87 μs, due to the larger thermal conductivity of silica relative to polymer in the proposed hybrid configuration.